This Core will serve as a vital resource center for blood and tissue-based studies integral to the completion of investigational projects, related to aggressive, interventional treatment of cerebral hemorrhage and ischemic infarcts. It will bring to analyses of blood and tissues derived from study patients a wealth of expertise in morphoanatomical techniques pertinent to stroke pathogenesis, and provide access to key investigators of samples of brain tissue derived from biopsy and autopsy specimens of study patients. The core will support Project 1, the MR RESCUE trial, in which intravascular thrombus material will be removed in the course of therapeutic thrombectomy. The core will assist investigators studying the biochemical pathogenesis of thrombus formation, and its possible importance in evolution of cerebral infarcts, and will assist investigators in correlating their findings with light microscopic/ultrastructural features of the thrombi. The core will also provide support to Project 2, the HEME Surgery trial, in which brain tissue originating from 'clot' evacuations carried out in patients with spontaneous intracerebral (parenchymal) hemorrhage will be carefully evaluated for both the likely etiology of hemorrhage and the tissue response to intracerebral blood, and readied for studies of differential gene expression employing qualitative, real-time RT-PCR and cDNA arrays. The Core will store blood samples from appropriate patients for DNA analysis, and provide these to researchers following appropriate review of their investigational goals and projects. The Core will serve as an important 'blood and brain tissue' resource to SPOTRIAS investigators at UCLA, and a larger network of investigators with interests in the treatment of acute ischemic and hemorrhagic stroke.